JPH04229534A - Cathode-ray tube - Google Patents

Abstract

PURPOSE: To provide a cathode ray tube with a rectangular face plate panel, having an aspect ratio of about 16/9 that means the ratio of the length of two long sides to the length of two short sides. CONSTITUTION: A cathode-ray tube is provided with a face plate panel having a long axis parallel to two long sides and a short axis parallel to two short sides. A rectangular observation screen is arranged on the inner face of the face plate panel. The radius of curvature of the long side in a plane containing the long axis and the short axis is about seven to ten times the diagonal dimension of the observation screen, and the ratio of the radius of curvature of the long side to the radius of curvature of the short side is within the range of about 1.6 to 1.9.

Description

[Detailed description of the invention]

0001

TECHNICAL FIELD This invention relates to cathode ray tubes (CRTs), and more particularly to CRTs having a faceplate panel with a perimeter shape of approximately 16.times.9 rectangular aspect ratio.

0002

BACKGROUND OF THE INVENTION Television cathode ray tubes commercially available to date have viewing screens and panels with a 4.times.3 aspect ratio. The aspect ratio referred to here is the ratio of the width, or horizontal dimension, to the height, or vertical dimension. However, as television systems with higher resolutions are introduced into commercial televisions in the near future, cathode ray tubes with wider aspect ratios will be required. Most movies are shot with an aspect ratio of approximately 22x9. However, cathode ray tubes with a 22x9 aspect ratio are extremely heavy for their dimensions, so cathode ray tube manufacturers have standardized on a lower 16x9 aspect ratio as a compromise with future high resolution systems.

0003

Early developed cathode ray tubes constructed with a 16.times.9 aspect ratio had faceplate panels that included peripheral sides with relatively large curvature. The purpose of curving the peripheral sides is to provide a panel with sufficient strength to withstand the surrounding pressure when the tube is evacuated. A disadvantage of panels with highly curved peripheral sides is that additional space must be provided in the television receiver cabinet to accommodate the cathode ray tube. However, designers of television receivers desire cabinet dimensions to be as small as possible and as light as possible. While making cathode ray tubes with straight side panels minimizes tube dimensions, it also requires an undesirably large lath thickness, which adds weight to the tube. become. Therefore, there is a need for a cathode ray tube design that provides a compromise between minimizing the height and width of the cathode ray tube panel and minimizing the weight of the cathode ray tube.

0004

[Means for Solving the Problems] The present invention provides a rectangular shape having two long sides and two short sides, and the ratio of the length of the long side of the periphery to the length of the short side of the periphery is about 16/9. Face plate・
An improved cathode ray tube including a panel is provided. The cathode ray tube has a long axis parallel to two long sides and a short axis parallel to two short sides, and a rectangular viewing screen is provided on the inner surface of the faceplate panel. In the improved cathode ray tube according to the present invention, the radius of curvature of the long side of the panel in a plane containing the major and minor axes is about 7 to 10 times as large as the diagonal dimension of the viewing screen. Further, the ratio of the radius of curvature of the long side to the radius of curvature of the short side is within the range of about 1.6 to 1.9.

[0005]

[Operation] The above conditions can provide the optimum design conditions for a cathode ray tube having an aspect ratio of 16.times.9.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a rectangular color cathode ray tube 10 having a glass bulb or envelope 11 consisting of a rectangular faceplate panel 12 and a tubular neck 14 joined by a rectangular funnel 15. Funnel 1
5 has an internal conductive coating (not shown) extending from the anode button 16 to the neck 14. Panel 12 is a rectangular observation face plate 1
8 and a peripheral flange or side wall 20 sealed to the funnel 15 by a glass frit 17. A three-color phosphor screen 22 is formed on the inner surface of the faceplate panel 18, preferably consisting of a linear screen with phosphor lines arranged in triplets, each having three color phosphor lines. Each set includes lines of phosphor in three colors. Screen 22 may be a dot-type screen, which may or may not include a light absorbing matrix. A porous color selection electrode or shadow mask 24 is detachably attached to the screen 22 at a predetermined distance. An electron gun 26, shown schematically by dotted lines in FIG. Aim at the screen 22.

The cathode ray tube of FIG. 1 is designed to be used with an external magnetic deflection yoke, such as yoke 30 shown near the junction of funnel 15 with neck 14. When energized, the yoke 30 applies a magnetic field to the three beams 28, causing the three beams to scan horizontally and vertically in a rectangular raster on the screen 22. Although the initial plane of deflection (0 deflection position) is approximately at the center of the yoke 30, the edge field actually causes the deflection region of the tube to extend axially from the yoke 30 into the area of the electron gun 26. To simplify the illustration, the actual bending of the deflected beam path in the deflection region is not shown in FIG.

As shown in FIG. 2, the rectangular faceplate panel 12 has two perpendicular axes, the long axis
, a short axis Y, and two diagonal axes D. The two peripheral long sides L of the faceplate panel 12 are substantially parallel to the long axis X, and the two short sides S are substantially parallel to the short axis Y. Preferably, both the long and short sides of the faceplate panel are curved in the X, Y, and D planes, and the ratio of the radius of curvature of the long side to the radius of curvature of the short side is about 1.6.
It is within the range of 1.9 to 1.9. Also, the ratio of the radius of curvature of the long side to the diagonal dimension of the screen is within a range of about 7 to 10. These ranges represent optimal design conditions for a cathode ray tube with a 16x9 aspect ratio.

The following Table 1 shows the 16×9
Three examples (1-3) representing dimensions and ratios of faceplate panels with aspect ratios, conventional 16x9
Two examples (4, 5) showing dimensions and ratios of faceplate panels with aspect ratios, and regular 4x3
Three examples representing each dimension and ratio with aspect ratios (6-
8).

0010

[Table 1]

[0011]

FIG. 3 is a composite diagram showing the curved states of the long and short sides of three types of face plate panels having an aspect ratio of 16×9, including panels with straight sides 32, a prior art panel with sides 34 of large curvature;
Figure 3 shows a novel panel according to the invention with edges 36 of small curvature. From an aesthetic and spatial point of view, panels with sides 32 represented by straight lines are most preferred. However, the stress of a panel with straight sides 32 is relatively high, requiring the panel to be considerably thicker and heavier than prior art panels. Prior art panel designs allow for the use of thinner and lighter glass, but increase the curvature on each side of the panel, require a television cabinet with more space, and reduce product quality. It becomes bulky. Faceplate panels constructed in accordance with the present invention require less space in the receiver cabinet and are slightly lighter than conventional panels. Finite element calculations performed on the novel panel according to the invention showed that the stress in the glass of the novel panel was greater than the stress in the glass of the prior art panel; When assembled into a tube with implosion protection means provided thereon, the cathode ray tube with the new panel showed no greater implosion potential than prior art cathode ray tubes.

[Brief explanation of the drawing]

FIG. 1 is a side view of a shadow mask type color cathode ray tube according to an embodiment of the present invention, partially cut along the axis.

FIG. 2 is a plan view of the back side of the face plate of the cathode ray tube of FIG. 1;

FIG. 3 shows a straight side, a conventional curved side, and a novel curved side according to the present invention superimposed together in one quadrant of a faceplate panel.

[Explanation of symbols]

10 Cathode ray tube 12 Rectangular face plate panel 22 Rectangular observation screen L Long side S Short side X Long axis Y Short axis

Claims (1)

[Claims] 1. A cathode ray tube comprising a rectangular faceplate panel having two long sides and two short sides, with a ratio of the length of the long side to the length of the short side of about 16/9. hand,
a rectangular viewing screen on the inner surface of the faceplate panel; a rectangular viewing screen on the inner surface of the faceplate panel; The radius of curvature in the plane including the axis is about 7 to 10 times the diagonal dimension of the observation screen, and the ratio of the radius of curvature of the long side to the radius of curvature of the short side is about 1.6 to 1. The above cathode ray tube within the range of No. 9.